Synthesis and characterization of Ca<SUB>2</SUB>CoTaO<SUB>6</SUB>, a new monoclinically distorted double perovskite

Abstract

The new Ca<SUB>2</SUB>CoTaO<SUB>6</SUB> double perovskite has been synthesized by a conventional solid state reaction and its unit cell parameters determined by X-ray powder diffractometry. It crystallizes in the monoclinic space group P2<i>1</i>/n. The unit cell parameters are: <i>a</i> = 5.507(2) Å; <i>b</i> = 5.564(3) Å; <i>c</i> = 7.798(3) Å; β = 89.99(4)° and Z = 2. The IR spectrum of the material was recorded and is briefly discussed. Some comparisons with Ca<SUB>2</SUB>CoNbO<SUB>6</SUB> and other isostructural perovskites are also performed.